Railway signaling apparatus



Feb. 24, 1942. E. M. ALLEN RAILWAY SIGNALING APPARATUS Filed July 27, 1940 INVE Earl A NTOR HIS ATTORNEY Patented Feb. 24, 1942 UNITED STATES PATENT OFFICE w Y 2,274,289 I I" V RAILWAY SIGNALING APPARATUS Earl M. Allen, Swissvale, Pa, 'assignor'to The Union Switch '& Signal Company, Swissvale,

Par, a corporation of Pennsylvania Application July 27, 1940, Serial No. 347,971

I I 10 Claims.

My invention relates to railway signaling apparatus; and it has particular referenceto the organization of such apparatus into railway signaling systems of the class incorporating means for controlling opposing-traflic movements over a stretch of single track railway and/or over a gauntlet track. I

It has been customary heretofore to control opposing traific movements over a single track railway and/or gauntlet by means of line wires" which'extend along the trackway and which are utilized to control the signaling apparatus to establish the proper signal indications'permitting traffic movement in one direction or the other while preventing movement in the opposite -out the use of line wires opposing traffic movements over a stretch of railway track.

Another object of my invention is to provide a novel and improved signal system particularly adapted for use with portions of a single track railway where difiiculty is experienced in providing and/or -maintainingline wires or auxiliary :3=;

conductors, extending along the trackway.

A further object of myinvention is the provision in a signal system for a single track railway,

of novel and improved means effective when a train enters either of two approach sections, one

at each end of an intermediate section, for controlling without the use of line wires signals governing traffic over the intermediate, section in such manner as to permit the train to proceed through the intermediate section and at the same time prevent trains operating in the;opposite direction from proceeding throughthe section.

The above-mentioned and other important objects and characteristic features of my invention which will become readily apparent from the following description, are attained in accordance with my invention by controlling opposing traffic movements over a stretch of track through the medium of two relaysandztwo means for supplying currents of opposite polarities to the two ends of the stretch, respectively, Means responsive to a train approaching either end of the stretch is utilized to'render ineffective the one current sup- @plying means adjacent the end approached by it) I the train, and to render effective the oneof the two relays located adjacent this end,.and other means is provided for maintaining inefiective'the selected onecurrent supplying means until the stretch of track is vacated bythe train.

I shall describe one formof apparatus embodying my invention, and shall then point out the novelfeatures thereof in claims.

The accompanyingdrawing is a diagrammatic view illustrating a preferred form of apparatus embodying my invention.

Referring to the drawing, the reference char acters I and la designate the track rails 'ofa stretch of single-track railway over which traffic operates in either direction, and which stretch is divided by means of the usual insulated rail 3joints-2 into a plurality of successive adjoining and shall refer to sections D-E and F-'-H asapproach sections for section E-F.

The reference characters SE and SF'desig-nate traffic controlling signals disposed one at, each end of section E-F to govern opposing .trafiic movements over the section. These-signals may be of any desired type, but as shown each signal comprises a "green lamp G and a red lamp ,3,

which lamps when illuminated indicate ,pro

ceed and stop, respectively. As shown, each signal normally isdark, and is control'led in a manner to be explained presently to an illuminated condition when the sectionin approach of the signal becomes occupied. d

The approach sections 13-12.. and F-I-Iare provided with track circuits each comprising a suitable source of current, such as a track battery, 3, connected to the rails at one end ofthe section and a track relay, designated by the reference character TR with a suitably distinguishing suffix, connected to the rails at the other endof the section over back contacts of an associated stick relay EBSR or WBSR, which relays will be referred to in more detail presently.

he reference characters WBTB and *EBTB designate current supplying means such as, for example, track batteries, connected to thetwo ends, respectively, of section E-=F to supply currents of opposing polarities tothe rails. One

terminal of battery WBTB is connected directly to the lower rail la of section E-F, and the other terminal of the battery is connected through an adjustable resistor 6, asymmetrical unit I in its low resistance direction, and front contacts .8 and 9, in multiple, of relay TRE, to the other rail l of the section. Similarly, one terminal of battery EBTB is connected to lower rail la and the other terminal of this battery is connected through resistor I0, asymmetrical unit II in its low resistance direction, and front contacts [2 and IS, in multiple, of relay TRF, to the other rail l of section EF. As is readily apparent from an inspection of the drawing, the connections of the two batteries to the rails of section EF are such that the two batteries supply currents of opposite polarities to the rails, and the apparatus preferably is adjusted in such manner that the resultant of the currents normally available in the rails of section EF is substantially zero. The asymmetricalunits 1- and II, interposed between rail I and one terminal of batteries WBTB and EBTB, respectively are provided further to assure that one battery does not cause current to flow in thereverse direction through the other battery in the event that'the apparatus gets out of adjustment or the terminal voltages of theltwo batteries become unbalanced. That is to say, if one battery becomes effective to impresson the trackrails a voltage higher than the other battery, the asymmetrical unit associatedwith such other battery presents its high resistance direction to the electromotive force of the one battery and hence such unit is effective to prevent a current flow in the reverse direction through the other battery.

The reference characters EBTR and W'BTR designate track relays one for each end of section EF. Both relays EB'I'R. and WBTR are normally disconnected from the rails of the section, and hence such relays normally are ineffective, but as will be made clear presently, at times the battery at one end or the other of section EF is disconnected from the rails of th section and relay EBTB. or WBTR, as the case maybe, at that end of the section is connected in circuit with the track rails.

stick relay associated with relay TRE for controlling the connection of the latter relay to the rails of the approach section D-E, as pointed out previously, and the reference character WBSR designates a stick relay provided for relay TRF for controlling the connection-of that relay 1 to the rails of section FI-I. Relays EBSR and W'BSR are provided each with a stick circuit and a pick-up circuit, which circuits will be pointed out presently.

The reference characters ETP and FTP designate slow pick-up auxiliary relays provided for relays 'I'RE and THE, respectively, which relays are controlled over circuits which will be traced in detail as the description proceeds.

The apparatus embodying my invention is in its normal condition, as represented in the drawinggwhen sections D--E, EF and FH are unoccupied. In this condition of the apparatus, relays TRE and TRF-are connected over back contacts of stick relays EBSR and WBSR, re-

spectively, to the rails of the associated approach sections and relays TRE and TRF accordingly are energized; batteries WBTB and EBTBare connected over front contacts of relays TEE and TRF, respectively, to the rails of section E-F and supply currents of opposite polarities to such rails; relays EBTR and WBTR. are disconnected from the rails of section EF and as a result are released; relays EBSR, EBHR, ETP, WBSR, WBHR and FTP are also released; and signals SE and SF are dark.

I shall now assume that with the apparatus in its normal condition above described, an eastbound train, that is, a train operating from left to right as viewed in the drawing, enters approach section D-E and shunts relay TRE to release that relay and open the connection of battery WBTB to the rails of section E--F at front contacts 8 and 9 of relay TRE. Battery WBTB is thus rendered ineffective to supply current to the rails of section EF whenever a train occupies the approach section adjacent the end of section E-F at which battery WBTB is connected, so that as a result only the other battery EBTB, connected at the opposite end of section EF, is effective to supply current to the rails of the section.

Relay TRE in releasing also closes its back contacts 25 and 26 to connect relay EBTR in circuit with the rails of section E-F, the connection passing from lower rail la of section EF through the winding of relay EBTR, back contacts 21 and 28, in multiple, of relay ETP, and back contacts 25 and 26, in multiple, of relay TRE to the other or upper rail 1 of the section. Relay'EBTR accordingly becomes energized in response to the current supplied by battery EBTB to the rails of section E-F, and relay EBTR picks up to complete at its front contact l6 the obvious energizing circuit for relay EBHR, When relay EBHR picks up, signal SE is controlled to its proceed indication over a circuit which extends from one terminal B of a suitable source of current, such as a battery not shown, through back contact 30 of relay TRE, front contact 3| of relay EBHR, and the filament of lamp G of'signal SE to the other terminal C of the source of current.

Under the above assumed conditions, the other signal SF remains in its dark condition, but if with the section D--E occupied and signal SE clear, another train enters the other approach section F-H, signal SF then is controlled to an illuminated stop indication. Under such latter conditions, that is, with section D--E occupied and signal SE clear, the entrance of the second train in section F-H causes relay TRF to release and open its front contacts l2 and I3 to disconnect battery EBTB from the rails of section E-F, and as a result relay EBTR, energized by current supplied from battery EBTB,

also releases to open the energizing circuit of relay EBHR. The slow releasing characteristics of relay EBHR are effective, however, to maintain that relay picked up until such time as slow pick-up relay F'IP provided for relay TRF picks up over a circuit extending from terminal B through back contact 33 of relay TRF, back con-' tact 34 of relay WBTR, back contact 35 of relay WBSR, and the winding of relay FTP to terminal 0. When relay FTP picks up, an alternate path around front contacts I2 and I3 of relay TRF is provided for connecting battery EBTB to the rails of section E-F, this path extending from the left-hand terminal, as viewed in the drawing, of battery EBTB through resistor l0, asymmetrical unit H, front contacts 31 and 38, in multiple, of relay FTP and back contacts 39 and 40, in multiple, of relay TRF to rail I of section E--F. Relay EBTR thereupon picksupin'respons to current received from the rails of section E'F', to close its front contact [6 and reenergize relay'EBHR. signal SE accordingly is caused to maintain the display of its proceed'indication when section F-H becomes occupied after section D-E becomes occupied, and under such assumed conditions signal SF is caused to display its stop indication over a circuit which extends from terminal B through back contact M of relay TRF, back contact 42 of relay WBHR and the filament of lamp R of signal SF to terminal C.

If, now, the train in section D-E accepts the proceed indication of signal SE and enters section E--F, relay E'BTR. is shunted and releases to open the energizing circuit of relay E-BHR at front contact it. During the slow release interval of relay EBI-IR, relay EBSR. becomes energizedover a pick-up circuit which may be traced from terminal B through back contact 44 of relay TRE, back contact 45 of relay EBTR, front contact 46 of relay EBHR and the winding of relay EBSR. to terminal C; and relay EBSR in picking up closes its front stick contact 41 to close around front contact 46 of relay EBHR. an alternate path which holds relay EBSR energized after relay EBHR releases to open its front contact 46. The releasing of relay EBHR also opensfront contact 3| to cause the proceed circuit of signal SE to become opened and the closing of back contact 48 of this relay completes an obvious circuit for lamp R of signal SE, thus causing the signal to display its stop indication.

When the train vacates section D E, relay TRE remains released since it circuit connection to the rails of section DE is open at back contacts [9, and 2|, in multiple, of relay EBSR, and relay TRE accordingly remains deenergized until the train vacates section E-F. Before this happens, however, the train enters the other approach section F- -H so that relay TRF is shunted and releases to pickup relay FTP and connect battery EBTB to the rails of section E-F over back contacts 39 and of relay TRF and front contacts 31 and38 of relay FTP, as pointed out previously.

When the train vacates intermediate section E-F, relay EBTR picks up in response to current supplied from battery EBTB, and opens its back contact to open the stick circuit of relay EBSR so that this latter relay releases to close its back contacts I9, 20 and 2! to connect relay TRE in circuit with the rails of section DE. If, at this time, this section is occupied by a following train, relay TRE remains released and relay EBHR picks up to operate signal SE to its proceed indication in the manner pointed out heretofore, thereby permitting the following train to proceed through section EF. In the event, however, that section DE is unoccupied when relay EBSR releases, relay 'I'RE picks up to open back contacts 25 and 26 and disconnect relay EBTR from the rails of section EF, and to connect over front contacts 8 and 9 battery WBTB to the rails in opposition to battery EBTB. The picking up of relay TRE also opens back contact 30 to control signal SE to its dark condition, and the apparatus at the left-hand end, as viewed in the drawing, of section EF is restored to its normal condition.

The remainder of the apparatus is restored to its normal condition when the train vacates section F-H and relay TRF picks up to connect battery EBTB to the rails/of section E-F over frontjconta ts l2 and Hand to open the circuit of relay FTP, whereupon the latter relay releases. Also, signal SF is controlledto its dark condition when'rel'ay 'I'RFpicksup to open back contact 4|. From the foregoing description, it is readily apparent that apparatus embodying my invention provides means whereby directional control of traifi-e over a common stretch of track may be established without using line wires, in such manner that a train first entering either of two approach-sections is signaled to proceed while another'train entering the other approach'sec tion is signaledto stop. The common section of track protected by signals in accordance with my invention may, of course, be an intermediate section separating two approach sections pro= vided for a single track railway, as shown in the drawing, or it may be a gauntlet with one ap proach section at one end of the gauntlet for one track and another approach section at the other end of the gauntlet for the other track. Inaddition, the signals controlling trafilc over the common portion of the trackway may be employed asmanual block signals controlled by snap switches, etc., in the usual manner. It is believed that the operation of the apparatus embodying my invention for a westbound train operating from right to left on the track will readilyb apparent from an inspection of the drawing together' with the foregoing description of the operation for an eastbound train, and further detailed explanation is deemed unnecessary.

Although I have herein shown and described only one form of railway signaling apparatus embodying my invention, it is understood that various changes and modifications may be made therein'withi'n the scope .of the appended claims without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is: 1. In combination, asection of railway track,

means located at each end of said section for supplying track circuit currents of opposing polarities to the rails, means controlled by a train approaching said section to render ineffective the current supplying means at the entrance end of the section and to connect a relay in circuit with the rails, and means controlled by said relay to maintain inefiective the'current supplying means at the entrance end of the section until said section'is vacated.

2. In combination, a section of railway track, means located at each end of said section for supplying track circuit currentsof opposing polarities to the rails, two relays one for each end of said section and each normally disconnected from the rails, means responsive to a train approaching either end of said section to render ineffective the current supplying means at the end of the section to be entered and to connect the relay at that end to the track rails, and means controlled by said relay to maintain ineffective the current supplying means at the entrance end of the section until said section is vacated.

3. In combination, a section of railway track, means located at each end of said section for supplying track circuit currents of opposing polarities to the rails, two relays one for each end of said section and each normally disconnected from the rails, mean responsive to av train approaching either end of said section to render ineffective the current supplying means at the-end of the section to be entered and to connect the relay at that end to the track rails, means controlled by said relay to maintain ineffective the current supplying means at the entrance end of thesection until said section is vacated, and signals controlling opposing traific movements over said section controlled by said two relays.

4. In-combination, a section of railway track, two batteries one located at each end of said section for supplying track circuit currents of opposingpolarities to the track rails, two relays one for each end of said section for receiving current from the rails but normally deenergized, means responsive to a train approaching either end of said section to render ineffective the battery at the end to be entered and to energize by urrent from the track rails the relay at that end, and signals controlling opposing traffic movements over said section controlled by said two relays.

5. In combination, a section of railway track, two batteries one located at each end of said section for supplying track circuit currents of opposing polarities to the track rails, two relays one for each end of said section for receiving current from the rails but normally deenergized, means responsive to a train approaching either end of said section to render ineffective the battery at the end to be entered and to energize by current from the track rails the relay at that end, means controlled by said relay to maintain ineffective the battery at the entrance end of the section until said section is vacated, and signals controlling opposing traflic movements over said section controlled by said two relays.

6. In combination, a track section, two batteries one located at each end of said section and normally effective to supply currents of opposing polarities to the rails, two relays one for each end of said section and each normally disconnected from the track rails, means responsive to a train approaching either end of said section to render ineffective the battery at the end of said section to be entered by the train and to connect the relay at that end to the track rails, two stick relays one for each of said relays and each provided with a pick-up circuit controlled by the associated relay, and means controlled by the stick relay associated with the one relay at the entrance end of said section to maintain ineffective the battery at the entrance end until said section is vacated.

'7. In combination, a track section, two batteries one located at each end of said section and normally effective to supply currents of opposing polarities to the rails, two track relays one for each end of said section and each normally disconnected from the track rails, signals for said section governed by said two relays, means responsive to a train approaching either end of said section to render inefiective the battery at the end of said section to be entered by the train and to connect the track relay at that end to the track rails, two stick relays one for each of said track relays and each provided with a pick-up circuit controlled by the associated track relay, and means controlled by the stick relay associated with the one track relay at the entrance end of said section to maintain ineffective the battery at the entrance end until said section is vacated.

8. In combination, a first section of railway track, two approach sections one at each end of said first section, two signals one at each end of said first section for governing opposing traffic movements over said section, two normally energized track relays one for each approach section, means controlled by the one of said two relays associated with the approach section first entered by a train for clearing the signal governing that train, and means responsive to traffic in said first section for retaining said one relay released and for preventing the clearing of the other signal if the other approach section becomes occupied during the interval that the train occupies either said one approach section or said first section.

9. In combination, a section of track intermediate two approach sections, two signals one at each end of said intermediate section for governing opposing trafiic movements over the section, two normally energized track relays one for each approach section, two means one at each end for supplying the rails of said intermediate section with currents of opposing polarities, two other relays one for each end of said intermediate section and each normally disconnected from said section, means controlled by the one of said two track relays associated with the approach section first entered by a train in a direction to pass through said intermediate section for rendering ineffective the current supplying means at the end of said intermediate section adjacent such entered approach section and for connecting to the rails of said intermediate section the associated other relay at that end of the section, means controlled by said two other relays for controlling said signals, and means controlled by said two other relays for maintaining ineffective the said current supplying means until the train vacates said intermediate section.

10. In combination, a section of railway track, means located at each end of said section for supplying track circuit currents of opposing polarities to the rails, asymmetrical units one for each current supplying means for preventing a reverse current flow through its associated means, means controlled by a train approaching said section to render ineffective the current supply- 7 ing means at the entrance end of the section and to connect a relay in circuit with the rails, and means controlled by said relay to maintain inefiective the current supplying means at the entrance end of the section until said section is vacated.

EARL M. ALLEN. 

